A cocktail hydrogel promoting the functional interneurons regeneration of human neural progenitor cells for brain injury therapy.

Abstract

INTRODUCTION: Traumatic Brain Injury (TBI) usually leads to substantial mortality and disability among adult populations. Neural progenitor cells (NPCs) transplantation exhibits great potential in TBI treatment. However, the differentiation rate of interneurons is relatively low, largely impeding the therapeutic effects of brain tissue repair. OBJECTIVES: A cocktail hydrogel (BGA@GelMA) was developed to provide a sustained release of neurotrophic factors and neural signaling molecules, thereby promoting the maturation of cortical interneurons, which can be utilized to improve the therapeutic outcomes of hNPCs transplantation for cerebral injury treatment. METHODS: The cocktail strategy (BGA@GelMA) was developed by integrating a hydrogel with neural inducers, and was characterized using cryogenic scanning electron microscopy (cryo-SEM), rheological tests and release kinetics. The potential of the BGA@GelMA hydrogel to differentiate hNPCs into cortical interneurons and to facilitate neural networks formation was analyzed with transcriptomic analysis, transsynaptic rabies virus tracing, flow cytometric analysis, immunofluorescence staining, and quantitative reverse transcription polymerase chain reaction (RT-qPCR). To enhance the efficiency of cell-based therapies, human pluripotent stem cells (hPSCs)-derived hNPCs encapsulated within the BGA@GelMA hydrogel were transplanted into a rat TBI model. The brain tissue repair was assessed using hematoxylin and eosin (H&E) staining, immunofluorescence staining, magnetic resonance imaging (MRI), motor evoked potential (MEP) recordings, and behavior tests. RESULTS: The synergistic role of micro- and nano-characterization, mechanical properties and multiple inducers-rich environment facilitated the maturation of cortical interneurons and the formation of synapses. Furthermore, after transplantation into the motor cortex of a rat TBI model, hNPCs embedded within BGA@GelMA hydrogel successfully enhanced brain recovery by differentiating into cortical interneurons, reducing the inflammatory response, and regenerating Neurovascular-like Unit (NVU). CONCLUSION: This cocktail hydrogel provided a novel strategy for improving the effect of hNPCs transplantation for cerebral injury treatment.